WebAIM - Web Accessibility In Mind

Cognitive Disabilities Part 1
We Still Know Too Little, and We Do Even Less


Cognitive disabilities are the least understood and least discussed type of disability among web developers. As a result, developers rarely design web content to be accessible to people with cognitive disabilities. This is unlikely to change overnight, because the amount of research related to the accessibility of web content is relatively scarce. Without a large body of research, the information about designing for people with cognitive disabilities is more speculative, more vague, and more difficult to implement. To complicate matters, many cognitive disabilities are ill-defined domains for research. Such disabilities are sometimes difficult to diagnose and characterize because of the wide variance between the characteristics of people who have similar cognitive disabilities.

In light of the problematic nature of defining and categorizing cognitive disabilities it should come as no surprise that the cognitive disability sciences have not yet yielded a well-defined set of recommendations for web developers. This isn't to say that no recommendations exist. Some recommendations have been incorporated into the W3C's Web Content Accessibility Guidelines. Others have been suggested elsewhere. The problem is that the scarcity of supporting research for these recommendations casts a shadow of doubt on their accuracy and completeness.

The first purpose of this brief article is to encourage more research in the field of content design for people with cognitive disabilities.

The second purpose of this article is to encourage developers to consider users with cognitive disabilities more seriously. There are far more users with cognitive disabilities than all the other types of disabilities combined (when you include learning disabilities, reading disorders, attention deficit disorders, and other common conditions).

The third purpose of this article is to publish and ask for feedback on a tentative list of recommendations.

The list of recommendations that follows is neither definitive nor comprehensive. Not all of these recommendations are easy to implement, nor even necessary in all circumstances. Not all of these recommendations are equally applicable to all kinds of cognitive disabilities. To complicate matters, some of these recommendations may appear to conflict with other accessibility recommendations. These conflicts may be real or not, depending on how the recommendations are implemented. Finally, not everyone in the cognitive disability field is likely to agree on the validity or accuracy of these recommendations. These recommendations are based on a combination of existing research, commonly-assumed best practices, and thoughtful speculation.

This list of recommendations can be useful to developers in its current state, but the hope is that researchers and developers will treat these recommendations as hypotheses to be tested. Please put these recommendations to the test! WebAIM is very interested in hearing about any research related to these topics.

Recommendations for Making Web Content Accessible to People with Cognitive Disabilities

  1. Create transformable, rich, multi-modal content.
    1. Transformable
      1. Allow fonts to be enlarged.
        The ability to enlarge fonts is dependent upon the capabilities of the user agent (browser), but relative units are recommended, rather than absolute units. For example, use "em" or "%" rather than "pt" or "cm."
      2. Use real text or vector-based text, rather than text within raster-based images, to allow for higher quality enlargement, without pixilation.
        Real text is always the best, most transformable method of conveying text content. When text is used within graphics or rich media, vector-based formats (flash, SVG) enlarge better than raster-based formats (e.g. jpg, gif, bmp).
      3. Provide all content in a text format so that it can be read aloud by text-to-speech synthesizers.
        Content can be in plain text, HTML, in alt text for images, or in any other format with true text that can be accessed by assistive technologies. It may be appropriate in some circumstances to provide the text version separate from the rich media version (e.g. text transcripts for videos).
    2. Multi-modal
      1. Illustrate concepts with drawings, diagrams, photos, audio files, video clips, animations, and other non-textual media.
        Communicate with the user through as many different sensory modalities and input modes as possible (sight, hearing, interaction, reading, etc.) to increase the chance that content will be understood.
      2. Provide synchronized captions and transcripts for the audio portion of time-based media.
        Add captions to video files (e.g. using SMIL or SAMI) and provide a link to a text transcript.
      3. Provide audio descriptions of visual events in time-based media.
        Narrate the visual actions in videos so that the video can be understood by listening to it, without watching it.
  2. Focus the attention of the user.
    1. Sensory focus
      1. Use softer colors (e.g. pastels) for graphical elements, rather than sharply contrasting colors. (Note: this is not widely accepted)
        When using background colors to differentiate sections of the same page, choose softer colors, rather than high contrast colors.
      2. Limit the types of font faces in a document.
        Use only one font, or a very small number of fonts in any single document.
      3. Limit or eliminate the use of italics or ALL CAPS.
        Avoid italics and all caps to the extent possible, to improve readability.
      4. Avoid background sounds that distract the user's attention (e.g. background music).
        Allow the user to focus on the main content without audio distractions.
      5. Use sounds to focus the user's attention (e.g. give instructions, alert the user to errors, etc.).
        Provide audible cues that help the user to focus on the main content.
      6. Include "white space"—non-content space—around the content, between paragraphs, and between headings.
        Don't crowd the design visually.
      7. Avoid complex or "busy" visual backgrounds.
        Don't create extraneous visual information that distracts from the main content.
    2. Content focus
      1. Place the important parts of a paragraph (key points) in the first sentence.
        Don't hide important points in the middle of paragraphs.
      2. Organize content into well-defined groups or chunks, using headings, bulleted lists, and other visual-semantic organizing schemes.
        Make the document's structure as obvious as possible.
      3. Highlight text as it's being read out loud (or allow users to activate this option).
        This recommendation is most applicable to rich media, such as Flash and SVG, that does not have native captioning capabilities, and where captions are added through programming or scripting.
      4. Emphasize important text—or the headings to sections of text—with bold font faces or larger text size.
        Use bold and/or large text to visually emphasize important text. Note: the default style of HTML headings is bold and large, so there is no need to use extra tags or markup to achieve this affect in HTML.
    3. Interaction focus
      1. Provide multi-modal navigational cues (e.g. text + graphical/visual highlight + auditory instructions + animated demonstration).
        Help users know what to do and how to interact with the content (e.g. create an audible voice that says "click the 'next' button to go to the next page", or a sound to accompany error messages, or visually highlight the "next" button, etc.)
      2. Give feedback on a user's actions (e.g. confirm correct choices, alert users to errors or possible errors).
      3. Provide instructions for unfamiliar interfaces.
  3. Design a consistent environment.
    1. Ensure that similar interface elements and similar interactions produce predictably similar results.
    2. Create a navigational scheme that is consistent across pages within a site or within related sections of a site.
  4. Create simple, concise content.
    1. Use clear and simple language.
      This recommendation is difficult to evaluate, but important.
    2. Avoid tangential information.
      Stick to the main topic.
    3. Use correct grammar and spelling.
      Use a spell-checker. Write well.
  5. Allow the user sufficient time to access and interact with content.
    1. Don't set short "expiration" times on content.
      To the extent possible, avoid time-dependent JavaScript, HTML auto-refreshing, and other types of timed redirects.
    2. If expiration times are necessary allow the user to request more time.
      Allow users to set preferences and/or alert users when time is about to expire and give them the option to extend the timeline.
  6. Allow users to recover from accidental and erroneous interactions.
    1. Ask users to confirm choices.
    2. Use shorter, multi-step forms for complex interactions, rather than lengthy, all-in-one forms.

Continue to part two of this articles - Conceptualizing Design Considerations